Histopathological, immunobiological, and biochemical techniques will be used for detecting and studying the mechanism of action of aspergillic mycotoxins in an animal model in which in vivo formation of aflatoxin (AF) occurs. Enzyme-linked immunsorbent analyses for AF and other Aspergillus toxins will be used to monitor their in vivo synthesis, to determine their metabolic fate, and to examine the nature of the actual species initiating neoplastic or other pathological changes during experimental aspergillosis. Immunocytochemical studies may lead to recognition of primary targets in host tissues at the molecular level. Aflatoxin-hormone interactions at cytoplasmic and nuclear hormone-receptor sites will be studied to learn possible mechanisms of AF-induced pathogenesis.